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Charge self-trapping in two strand biomolecules:Adiabatic polaron approach

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Chinese Physics B 2023年第1期32卷 253-263页

作者： d Chevizovich s Zdravković A V Chizhov Z Ivić University of Belgrade Vinča Institute of Nuclear SciencesP.O.Box 522Belgrade 11001Serbia Joint Institute for Nuclear Research Laboratory for Radiation BiologyDubna 141980Russia dubna state University Dubna 141980Russia department of Physics University of CreteP.O.Box 2208Heraklion 71003Greece National University of science and Technology MIsis Leninsky prosp.4Moscow 119049Russia

We investigate the properties of the excess charge(electron, hole) introduced into a two-strand biomolecule. We consider the possibility that the stable soliton excitation can be formed due to interaction of excess charge with the phonon subsystem. The influence of overlap of the molecular orbitals between adjacent structure elements of the macromolecular chain on the soliton properties is discussed. special attention is paid to the influence of the overlapping of the molecular orbitals between structure elements placed on the different chains. Using the literature values of the basic energy parameters of the two-chain biomolecular structures, possible types of soliton solutions are discussed.

关键词： charge self-trapping adiabatic polaron soliton two-stranded biomolecules

Effects of bottom shear stresses on the wave-induced dynamic response in a porous seabed:PORO-WssI (shear) model

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Acta Mechanica sinica 2011年第6期27卷 898-910页

作者： J.Ye d.-s.Jeng division of Civil Engineering University of Dundee Center for Marine Geotechnical Engineering State Key Laboratory of Ocean EngineeringShanghai Jiao Tong University

When ocean waves propagate over the sea floor,dynamic wave pressures and bottom shear stresses exert on the surface of *** bottom shear stresses provide a horizontal loading in the wave-seabed interaction system,while dynamic wave pressures provide a vertical loading in the ***,the bottom shear stresses have been ignored in most previous studies in the *** this study,the effects of the bottom shear stresses on the dynamic response in a seabed of finite thickness under wave loading will be examined,based on Biot＇s dynamic poro-elastic *** the model,an ＂u-p＂ approximation will be adopted instead of quasi-static model that have been used in most previous *** results indicate that the bottom shear stresses has certain influences on the wave-induced seabed dynamic ***,wave and soil characteristics have considerable influences on the relative difference of seabed response between the previous model（without shear stresses） and the present model（with shear stresses）.As shown in the parametric study,the relative differences between two models could up to 10% of p0,depending on the amplitude of bottom shear stresses.

关键词： Bottom shear stresses Wave-induced dynamicresponse Porous seabed - "u-p" approximation - Biot's the-ory

Notch severity Effect on Hydrogen Embrittlement of Type 4340 steel

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Journal of Materials science & Technology 1996年第1期12卷 51-56页

作者： Liu, s Zhu, ZY Ke, W Hardie, d UNIV NEWCAsTLE UPON TYNE DEPT MECH MAT & MFG ENGNNEWCASTLE TYNE TE1 7RUTYNE & WEARENGLAND

Hydrogen embrittlement of Type 4340 steel has been investigated by straining round-notched specimens in 10(5) Pa hydrogen atmosphere at a constent cross-head spead of 1.4x10(-4) mm/s. The circumferentially notched specimens exhibited a significant embrittlement when their mechanical behaviour in hydrogen was compared with that in air. Although the effect of notch depth on fracture strength in air is negligible, an increase in the depth of notch increase susceptibility to embrittlement when testing in gaseous hydrogen. However, analysis of the effects is complicated by the facts that (i) the specimens show some degree of notch severity even when strained in air and (ii) the behaviour is complicated by the localised plastic deformation that may occur for relatively shallow notches. such effects are eliminated at high stress concentration factors, so there is a systematic loss in fracture stress in hydrogen as the notch sensitivity increases from K-t=2.6 to 5.7 (where a 87% reduction of fracture stress occurs) but a relatively stable value is then reached even for very severe notching by fatigue pre-cracking. Whether or not the effect is due to increasing concentration of hydrogen in the triaxial stress region ahead of the notch, there is no doubt that increasing the stress concentration makes hydrogen more effective as an embrittlement agent.

关键词： Carbon steel

Finite deformation analysis of crack tip fields in plastically compressible hardening–softening–hardening solids

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Acta Mechanica sinica 2017年第1期33卷 148-158页

作者： d.Khan s.singh A.Needleman Mechanical Engineering department Indian Institute of Technology Banaras Hindu University department of Materials science & Engineering Texas A&M University College Station

Crack tip fields are calculated under plane strain small scale yielding conditions. The material is characterized by a finite strain elastic-viscoplastic constitutive relation with various hardening-softening-hardening hardness functions. Both plastically compressible and plastically incompressible solids are considered. displacements corresponding to the isotropic linear elastic mode I crack field are prescribed on a remote boundary. The initial crack is taken to be a semi-circular notch and symmetry about the crack plane is imposed. Plastic compressibility is found to give an increased crack opening displacement for a given value of the applied loading. The plastic zone size and shape are found to depend on the plastic compressibility, but not much on whether material softening occurs near the crack tip. On the other hand, the near crack tip stress and deformation fields depend sensitively on whether or not material softening occurs. The combination of plastic compressibility and softening (or softening-hardening) has a particularly strong effect on the near crack tip stress and deformation fields.

关键词： Plasticity Crack tip fields Fracture Compressible solids Material softening

shape effects on the ground-state energy of a three-electron quantum dot

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Chinese Physics B 2015年第12期24卷 488-493页

作者： Z.d.Vatansever s.sakiroglu .sokmen department of Physics Faculty of Science Dokuz Eylül University dokuz Eylül University Graduate School of Natural & Applied Sciences

In this work we will theoretically study the ground-state electronic structure of three-electron polygonal quantum dots by means of the configuration interaction method. Transition from a weakly correlated regime to a strongly correlated regime is investigated for quantum dots with hexagonal, square, and triangular geometries. Our numerical results reveal that the ground-state spin and the charge density distribution of the system are sensitive to the shape of the quantum dot.

关键词： quantum dot configuration interaction method Wigner molecule

Generation of unsteady waves by concentrated disturbances in an inviscid fluid with an inertial surface

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Acta Mechanica sinica 2008年第3期24卷 267-275页

作者： d.Q.Lu s.Q.dai shanghai Institute of Applied Mathematics and Mechanics Shanghai University200072 ShanghaiChina shanghai Key Laboratory of Mechanics in Energy and Environment Engineering 200072 ShanghaiChina

The surface waves generated by unsteady concentrated disturbances in an initially quiescent fluid of infinite depth with an inertial surface are analytically investigated for two- and three-dimensional cases. The fluid is assumed to be inviscid, incompressible and homogenous. The inertial surface represents the effect of a thin uniform distribution of non-interacting floating matter. Four types of unsteady concentrated disturbances and two kinds of initial values are considered, namely an instantaneous/oscillating mass source immersed in the fluid, an instantaneous/oscillating impulse on the surface, an initial impulse on the surface of the fluid, and an initial displacement of the surface. The linearized initial-boundary-value problem is formulated within the framework of potential flow. The solutions in integral form for the surface elevation are obtained by means of a joint Laplace-Fourier transform. The asymptotic representations of the wave motion for large time with a fixed distance- to-time ratio are derived by using the method of stationary phase. The effect of the presence of an inertial surface on the wave motion is analyzed. It is found that the wavelengths of the transient dispersive waves increase while those of the steady-state progressive waves decrease. All the wave amplitudes decrease in comparison with those of conventional free-surface waves. The explicit expressions for the freesurface gravity waves can readily be recovered by the present results as the inertial surface disappears.

关键词： Waves Inertial surface Concentrated disturbances Asymptotic representation

Role of asymmetry effect on the specific conductivity of water——A case study

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Chinese Journal Of Geochemistry 2012年第3期31卷 276-281页

作者： Parameswara d. Prasad K.s.s. dept.of Chemistry S.G.S.Arts CollegeTirupatiIndia dept.of Geology S.V.UniversityTirupatiIndia

Forty-one water samples in each season(both pre-and post-monsoon) were collected from different for-mations of the Kadiri schist belt located in the Anantapur district,Andhra *** specific electrical conductiv-ity(EC) of these water samples was measured at 25℃ by using specific conductivity *** specific conductiv-ity values of the water samples were also calculated by multiplying ionic concentrations with conductivity *** is found that the observed EC values of all water samples collected in both the seasons are different from the esti-mated EC values because of the electro-chemical properties of ions in water.

关键词：水样电导率不对称案例 EC值导热系数离子浓度化学性质

Large scale silver nanowires network fabricated by MeV hydrogen (H＋) ion beam irradiation

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Chinese Physics B 2016年第4期25卷 268-273页

作者： Honey s Naseem s Ishaq A Maaza M Bhatti M T Wan d Center of Excellence in solid state Physics University of the Punjab Lahore Pakistan National Center for Physics Quaid-i-Azam University Islamabad 44000 Pakistan UNEsCO-UNIsA Africa Chair in Nanosciences/Nanotechnology College of Graduate Studies University of South Africa Muckleneuk ridge P. O. Box 392 Pretoria South Africa Nanosciences African Network (NANOAFNET) iThemba LABS National Research Foundation Old Faure road P. O. Box 722 Somerset West 7129 South Africa department of Physics Bahauddin Zakariya University Multan 60800 Pakistan school of Materials science and Engineering Shanghai University Shanghai 201900 China

A random two-dimensional large scale nano-network of silver nanowires （Ag-NWs） is fabricated by MeV hydrogen （H＋） ion beam irradiation. Ag-NWs are irradiated under H＋ ion beam at different ion fluences at room temperature. The Ag-NW network is fabricated by H＋ ion beam-induced welding of Ag-NWs at intersecting positions. H＋ ion beam induced welding is confirmed by transmission electron microscopy （TEM） and scanning electron microscopy （sEM）. Moreover, the structure of Ag NWs remains stable under H＋ ion beam, and networks are optically transparent. Morphology also remains stable under H＋ ion beam irradiation. No slicings or cuttings of Ag-NWs are observed under MeV H＋ ion beam irradiation. The results exhibit that the formation of Ag-NW network proceeds through three steps： ion beam induced thermal spikes lead to the local heating of Ag-NWs, the formation of simple junctions on small scale, and the formation of a large scale network. This observation is useful for using Ag-NWs based devices in upper space where protons are abandoned in an energy range from MeV to GeV. This high-quality Ag-NW network can also be used as a transparent electrode for optoelectronics devices.

关键词： Ag nanowires H+ ion irradiation nanowelding large scale nano-network optical properties

Earthquake response of asymmetric building with MR damper

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Earthquake Engineering and Engineering Vibration 2014年第2期13卷 305-316页

作者： s.d.Bhart s.M.dumne M.K.shrimali department of Civil Engineering Malaviya National Institute of Technology Jaipur Govt.Poly.College Nashik Maharashtra India

Plan asymmetric buildings are very susceptible to earthquake induced damage due to lateral torsional coupling, and the corners of these systems suffer heavy damage during earthquakes. Therefore, it is important to investigate the seismic behavior of an asymmetric plan building with MR dampers. In this study, the effectiveness of MR damper-based control systems has been investigated for seismic hazard mitigation of a plan asymmetric building. Furthermore, the infl uence of the building parameters and damper command voltage on the control performance is examined through parametric study. The building parameters chosen are eccentricity ratio and frequency ratio. The results show that the MR damper-based control systems are effective for plan asymmetric systems.

关键词： torsional coupling plan asymmetric MR damper